Residents near the former Wurtsmith Air Force Base in Oscoda Township have become increasingly concerned over the past year as toxic fluorochemicals leaching through the groundwater have generated white foam that's washing ashore on public beaches and private waterfronts around the picturesque Van Etten Lake.

The foam contains alarmingly high levels of per- and polyfluoroalkyl substances known as PFAS or PFCs and locals consider it a worrisome manifestation of a toxic groundwater problem that, until now, has been out of sight and to some degree out of mind.

"We never had this type of foam before," said Greg Cole, who owns a lakefront cottage rental business with his wife, Vicky, and operates the Van Etten Creek dam, which allows Van Etten Lake water into the Au Sable River and Lake Huron.

A July 2017 test showed perfluorooctanesulfonic acid, or PFOS, in the foam at concentrations up to 165,000 parts per trillion (ppt), which is roughly 13,000 times Michigan's limit of 12-ppt for PFOS in surface waters like lakes, rivers or streams.

PFOS in the surrounding lake water has tested at 254-ppt.

The contamination level has strained the state's relationship with the Air Force, which is responsible for cleaning up the former nuclear B-52 bomber base. On Dec. 14, the Michigan Department of Environmental Quality initiated a formal dispute under a joint program, saying federal efforts are not adequately curbing the plumes.

The first granular activated carbon groundwater treatment system installed on the southwest side of the base in April 2015 "is not intercepting or containing the PFAS contaminated groundwater, nor is the system effectively preventing expansion of the plume," wrote acting DEQ remediation division director Kathleen Shirey.

"The USAF must move more aggressively and more quickly to define and remove the ongoing threat to public health and the environment."

On Jan. 19, the state issued a violation notice after the Air Force blew past a deadline to install a second PFAS treatment system on base -- a system that was supposed to be operational last year, but the Air Force says will go online this summer.

Whether that system will reduce lake foaming is a matter of debate. DEQ directors say the new system should have some effect on the plume entering the lake, but how much is an open question. Township officials don't believe it will do much.

Oscoda residents are frustrated with both state and federal efforts, arguing that the Air Force is moving slowly and tackling cleanup piecemeal. They want the state to be more aggressive with the military and more forthcoming with information.

Some are also skeptical that the foam is safe to touch.

The Van Etten Lake Association, Anglers of the Au Sable and Oscoda Township have each sent letters demanding the military clean up the plume entering the lake at the source.

Township officials characterize the foam as the latest symptom of a toxic problem that's metastasizing as the state and federal government bicker over how exactly the state's water quality standards apply to PFAS levels in Van Etten Lake.

What might seem simple at first blush -- lake contamination levels exceed state rules and therefore the Air Force must act to fix the problem -- is complicated by regulatory minutiae regarding exactly where samples are taken and which state rules apply.

The DEQ's Rule 57 Water Quality Value of 12-ppt for PFOS was developed in 2011 to guide fish consumption advisories and residents involved with a newly established citizen's cleanup advisory board say the state hasn't enforced it in Oscoda before.

Instead, the DEQ wants to rely on its Part 201 toxic cleanup criteria, which has 70-ppt enforceable limits on PFAS in groundwater.

Sue Leeming, DEQ external relations director and former remediation division chief, said the state needs sampling data from the very spot where groundwater enters the lake water; what's known as the groundwater-surface water interface (GSI).

To ensure that, more sampling is being scheduled.

"We think it's an issue and in order to confirm that, we have to have data from the appropriate monitoring spots," said Leeming. "That's what this new testing will do for us -- give us fresh data we are confident is coming from a GSI monitoring point."

Meanwhile, locals have a lake with toxic froth on top.

"Whenever the wind blows, the wave action causes (the PFAS) to regenerate into AFFF," said Aaron Weed, Oscoda Township supervisor.

Aqueous Film Forming Foam, or "A-Triple-F," is the original source of PFAS contaminating the groundwater. The synthetic foam was used to coat hydrocarbon fires. The flame-retarding PFAS chemistry suppresses combustion by keeping fuel from mixing with oxygen. It's highly effective at quashing jet fuel fires.

Leftover foam from old base fire training and airplane crashes created several huge PFAS plumes which have been seeping into nearby wetlands, the Au Sable River, Van Etten Lake and drinking water wells at homes around the base.

The state has been investigating PFAS at Wurtsmith since 2011, first in local fish and subsequently in drinking water. It was the first of what's become 14 locales around the state with known PFAS contamination.

In 2016, the Michigan Department of Health and Human Services escalated the alarm in Oscoda Township when it told local residents on private wells to find an alternative drinking water source because of the scope of chemical spread.

Renewed focus helped shake loose state and federal funding to extend municipal water mains down some streets, provide bottled water and filters, and re-establish the local advisory board, but residents are frustrated by the slow pace of actual cleanup work.

PFAS-contaminated runoff has particularly frustrated local officials, who've watched high PFAS levels entering the Au Sable River and Lake Huron for years. In September, testing showed a combined PFOS and PFOA level of 166,200-ppt entering the river at a storm drain outfall.

The discharge comes from a groundwater treatment system installed decades ago to remove volatile organic compounds like trichloroethylene. Although those levels had dropped enough by 2014 to stop pumping, the DEQ required the Air Force to keep the purge wells operating to slow the migrating PFAS plumes.

The DEQ told the Air Force it needed to treat the PFAS discharge in 2016. Construction finally began in January. The system should go online this summer.

Unfortunately, there are doubts about whether it will touch the PFAS plume entering Van Etten Lake at Ratliff Park, the public beach across from the base. That's where a group of Michigan State University research students who were denied access to the base found what at first appeared to be protein foam in July.

Testing confirmed a toxic calling card: PFOS, PFOA and PFHxS. "This is coming back almost entirely with an AFFF signature," said Weed.

On Dec. 6, the day of a community meeting involving the state, Air Force and local health department, Anthony Spaniola walked out of his home on the northeast shore of Van Etten Lake and saw "foam as far as the eye can see" in each direction along the beach.

Spaniola had been eyeing the foam with increasing concern after stumbling across contractors taking samples near the beach gazebo in August. At first, he said, neighbors were skeptical about the hazard, but they came around after he got his hands on state and federal test results showing extremely high PFAS levels in the foam.

Shortly thereafter, on Sept. 1, the state and local health departments issued a joint advisory recommending Labor Day visitors "avoid ingesting" the foam.

During the No Spills conference in Traverse City in January, Michigan DHHS toxicologist Christina Bush said the potential that young children might swallow the foam while playing on the beach helped prompt the warning. Exposure to the chemistry has been linked to certain cancers, thyroid malfunction and other diseases.

"We're saying avoid contact with it, but the concern we have is because of the possibility of swallowing it," she said. "Not because we have a concern about skin contact."

Bush said that because PFOS is a surfactant, a chemical microlayer on the water surface gets sudsy when wind conditions are right.

The foaming has also been observed on Lake Margrethe in Crawford County, where the DEQ is also conducting a PFAS plume investigation at the Camp Grayling Michigan National Guard base. The DEQ took foam samples from the lake late last year.

"It's different than the foam you'd see on disturbed water," Bush said, describing it as whiter and frothier. "It's like Mr. Bubbles suds."

Photos of the foam taken by Cole in December show a wide expanse near the lake's dam outlet, with patches that look like pancake ice.

When Leeming flew into Wurtsmith in December, the foam was visible as a "white ring around parts of the shoreline," she said.

"It's sticky and accumulates in piles," said Spaniola, a Troy attorney who thinks the Air Force should have to clean up the plume entering Van Etten Lake under the 12-ppt rule.

He argues the Air Force already acknowledged the Rule 57 limit applies to waters around Wurtsmith in a March 2017 letter to the state Senate Fiscal Agency, in which the military branch wrote it was working with the DEQ "to ensure compliance with" the rule related to polluted groundwater entering Clark's Marsh south of the base.

The letter was a response to passage of Public Act 545 of 2016, which required the state or federal government provide safe water to any property owner with a polluted well if the health department issued an advisory and the government caused the pollution.

The Air Force has fought compliance, saying the law discriminates. Air Force spokesperson Mark Kinkade said last year the Michigan law, Public Act 545 of 2016, does discriminate "as it only applies to federal and state agencies, not to all entities and persons," he said.

In contrast to the PFAS pollution caused by shoemaker Wolverine World Wide in Kent County, the Air Force will only provide a whole-house drinking water filtration unit for homes testing above the Environmental Protection Agency's 70-ppt health advisory level.

Only two Oscoda wells have tested above that limit. In Kent County, Wolverine is providing filters to many homes with any PFAS detection.

One of those Oscoda wells is in the middle of the Van Etten Lake plume. In 2016, it tested for 3,300-ppt PFOA, 96-ppt for PFOS and 12,000-ppt PFHxS. Total PFAS in the well was 19,734 ppt.

Attorney General Bill Schuette's office referred questions about PA 545 and Rule 57 to the DEQ and would not provide any information about the status of its involvement.

The military could be forced to conduct more cleanup measures under Michigan's new Part 201 criteria of 70-ppt for PFOS and PFOA in groundwater used for drinking water, although it's unclear whether that would apply to the plume entering the lake.

Spaniola is frustrated the state isn't being more aggressive about enforcing the existing PFOS surface water quality standard of 12-ppt.

The Air Force told MLive it's "not taking a position" on whether it believes Michigan's 12-ppt rule for PFOS "will apply to any particular response action."

The Air Force said it will "comply with any surface water quality criteria that are found to be applicable or relevant and appropriate under the circumstances," as determined by certain sections of the federal Superfund law, known as CERCLA.

In response to local demands for cleanup of the plume entering the lake, the Air Force said only that "the public will have the chance to weigh in on" the process during local advisory board meetings and subsequent investigation planning stages.

The Air Force doesn't plan any further foam testing.

That's not much comfort to residents like Greg and Vicky Cole.

"Being a business owner that depends on the lake and surrounding area for providing us its natural beauty, we are outraged at this poison dumping into our environment," Greg Cole said.